JP4232201B2 - Spark ignition direct injection engine - Google Patents

Description

  The present invention relates to a spark ignition direct injection engine, and particularly to a spark ignition direct injection engine including an injector having a plurality of injection holes.

  There is known a spark ignition type direct injection engine provided with an injector for directly injecting fuel into a combustion chamber. This type of engine is configured to improve fuel efficiency by performing fuel injection during the compression stroke, causing the air-fuel mixture to be unevenly distributed near the spark plug and performing stratified combustion. The present invention has been developed based on such a technique.

  In the direct injection engine as described above, under a predetermined condition such as at the time of full load, fuel is injected during the intake stroke, and the air-fuel mixture is uniformly distributed in the cylinder and burned uniformly. However, since the direct injection engine has a configuration suitable for performing stratified combustion by causing the air-fuel mixture to be unevenly distributed in the vicinity of the spark plug, an attempt is made to perform uniform combustion by fuel injection in the intake stroke in a high load region or the like. As a result, the air-fuel mixture becomes poorly vaporized or non-uniform, and a necessary torque cannot be obtained, and problems such as generation of smoke, particulates, and HC may occur at full load.

The inventors of the present invention, in a direct injection engine, devise the direction of the axis of the injector nozzle (center axis of fuel injection) and the like, thereby promoting the vaporization / mixing of the injected fuel and increasing the engine load. It has been found that the homogeneity of the air-fuel mixture in the combustion chamber can be improved also in the region.
The present invention has been made based on such knowledge, and an object thereof is to provide a spark ignition type direct injection engine capable of improving the homogeneity of the air-fuel mixture and performing uniform combustion with excellent characteristics. To do.

According to the present invention, a combustion chamber constituted by a cylinder, a cylinder head, and a piston, an ignition plug having an electrode portion disposed at the upper center of the combustion chamber, and an intake air disposed at a ceiling portion of the combustion chamber. A valve, an exhaust valve disposed at a position facing the intake valve across the ignition plug, an injector disposed adjacent to the intake valve and injecting fuel into the combustion chamber, and fuel injection from the injector A spark ignition type direct injection engine having a fuel injection control means for controlling the injector, wherein the injector includes an upper injection hole directed to the electrode portion and a plurality of lower injection holes directed to the piston. The angle formed between the axis of the upper nozzle and the axis of the lower nozzle adjacent to the upper nozzle is a half of the injection angle of fuel injection from the upper nozzle in the compression stroke and the compression stroke The angle of the center of two lower nozzles adjacent to each other among the plurality of lower nozzles is set to be larger than the sum of the angle of the fuel injection from the lower nozzle adjacent to the upper nozzle The angle between them is one half of the injection angle of fuel injection from one of the two lower nozzles in the compression stroke, and 2 of the injection angle of fuel injection from the other of the two lower nozzles in the compression stroke. It is set to an angle less than the sum of the angle of a minute ,
The upper nozzle hole is composed of three nozzle holes whose axial centers are directed to the left and right and lower regions of the spark plug,
The lower nozzle hole is composed of three nozzle holes whose axis is directed to the piston through the lowermost position of the intake valve.
A spark ignition direct injection engine is provided.

According to such a configuration, the fuel injected from the upper nozzle and the fuel injected from the lower nozzle do not interfere with each other and attract each other, so that the fuel injected from the upper nozzle is the electrode of the spark plug. The fuel injected from the lower nozzle near the part is reliably blown to the crown surface of the piston, and the air-fuel mixture can be surely unevenly distributed near the electrode part by the fuel from the upper nozzle.
Furthermore, since the axial centers of the adjacent lower nozzle holes are close enough that the fuel injections interfere with each other, the fuel injections from the lower nozzle holes attract each other and do not expand greatly. As a result, the fuel injected from the lower nozzle is prevented from adhering to the cylinder inner wall, and the occurrence of smoke and the like is suppressed.

According to another preferred aspect of the present invention, the piston is provided with a cavity formed on the crown surface and opening upward, and an axis of the lower nozzle is located at an intermediate height position of the cylinder. It is arranged to be directed into the opening edge of the cavity of the piston.
According to such a configuration, since the fuel sprayed into the cavity of the piston crown surface is efficiently dispersed in the combustion chamber, homogenization of the air-fuel mixture is promoted.

According to another preferred aspect of the present invention, the opening of the cavity has an oval shape whose major axis extends from the end on the exhaust valve side of the crown surface toward the end on the intake valve side.
According to such a configuration, since the opening of the cavity extends along the fuel injection from the injector, the injected fuel is reliably received in the cavity, the adhesion of the fuel to the cylinder wall is suppressed, and the combustion chamber is Distributed efficiently.

According to another preferred aspect of the present invention, the cavity gradually becomes deeper from the intake valve side toward the exhaust valve side.
According to another preferred aspect of the present invention, the fuel injection control means causes fuel injection to be executed from the beginning of the intake stroke in a high load or high speed region.
According to another preferred aspect of the present invention, the fuel injection control means causes fuel injection to be executed in the middle of the intake stroke in a high load or high speed region.
According to another preferred aspect of the present invention, an angle formed between the axis of the upper nozzle and the axis of the lower nozzle adjacent to the upper nozzle is set to 20 ° or more.

  ADVANTAGE OF THE INVENTION According to this invention, the spark-ignition type direct injection engine which can improve the homogeneity of air-fuel | gaseous mixture and can perform the uniform combustion of the outstanding characteristic is provided.

Hereinafter, a configuration of a spark ignition direct injection engine according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a spark ignition direct injection engine 1 according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the vicinity of a combustion chamber of the engine.
The engine 1 includes a cylinder block 4 formed with four cylinders 2 (only one is shown in FIG. 1) arranged in series, and a cylinder head 6 arranged on the cylinder block 4. . A piston 8 is disposed in the cylinder 2 so as to be able to reciprocate in the vertical direction.

A combustion chamber 10 is formed between the piston 8 and the cylinder head 6. As shown in FIG. 2, the combustion chamber 10 is a so-called pent roof type combustion chamber having two inclined surfaces extending from a substantially central portion of the ceiling portion of the cylinder 2 to the vicinity of the lower end surface of the cylinder head 6.
On the other hand, a crankshaft 12 is rotatably supported below the piston 8 in the cylinder block 4, and the crankshaft 12 and the piston 8 are connected via a connecting rod 14.

  As shown in FIG. 1 and FIG. 2, the cylinder head 6 has two intake ports 16 and two exhaust ports 18 in parallel (only one of them is shown in FIGS. 1 and 2). It is formed with. Each of the two intake ports 16 is opened on one inclined surface of the combustion chamber, and an intake valve 20 that is opened and closed at a predetermined timing is seated on each intake port 16. Each intake valve 20 has a generally circular shape and includes a valve umbrella portion 20a that opens and closes the intake port 16, and a rod-shaped stem 20b that extends from the center of the valve umbrella portion 10a. The two exhaust ports 18 are opened alongside the other inclined surface of the combustion chamber, and an exhaust valve 22 that opens and closes at a predetermined timing is seated on these exhaust ports 18.

  3 is a plan view showing a crown surface (top surface) of the piston 8, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. As shown in FIGS. 2 to 4, a concave cavity 9 opening upward is formed on the crown surface of the piston 8.

As shown in FIG. 3, the cavity 9 on the crown surface of the piston 8 is provided with an oval (substantially oval) upper end opening (opening edge 9a) having a wide exhaust valve side, and the length of the opening edge 9a is long. The direction axis A passes between the adjacent intake valves 20 and 20 and between the exhaust valves 22 and 22, and the crown positioned on the exhaust valve 22 side from the end of the crown surface located on the intake valve 20 side. It arrange | positions so that it may extend to the edge of a surface.
Further, as shown in FIG. 2, the cavity 9 is formed so as to gradually become deeper from the intake valve 20 toward the exhaust valve 22 side, and further, as shown in FIG. The opening edge 9a has an arcuate cross section (R shape).

  As shown in FIG. 1, an intake passage 24 that communicates with the intake port 16 of each cylinder 2 is connected to one side of the engine 1. The intake passage 24 is for supplying the intake air filtered by an air cleaner (not shown) to the combustion chamber 6 of the engine 1, and the intake sucked into the engine 1 sequentially from the upstream side to the downstream side. A hot wire air flow sensor 26 for detecting the amount of air, an electric throttle valve 28 for restricting the intake passage 24, and a surge tank 30 are arranged. The electric throttle valve 28 is not mechanically connected to an accelerator pedal (not shown) and is driven by an electric drive motor (not shown).

  Further, the intake passage 24 is branched into independent passages connected to the cylinders 2 on the downstream side of the surge tank 30, and the downstream end portion of the independent passages is further branched into two to provide two intake air for each cylinder. Each port 16 is connected.

  A spark plug 32 is disposed at the center of the upper portion of the combustion chamber 10 at substantially the center of the four intake / exhaust valves 20, 20, 22, 22. An electrode 32 a at the tip of the spark plug 32 is located at a position protruding a predetermined distance from the ceiling of the combustion chamber 10, and an ignition circuit 34 is connected to the base end of the spark plug 32. The ignition plug 32 is energized at a predetermined timing.

  An injector 36 is attached between the intake valves 20 at the peripheral edge of each combustion chamber 10. The injector 36 is a so-called multi-hole injector in which a plurality of injection holes are formed at the tip, and is disposed so as to face the exhaust valve 22 with the electrode portion 32a of the spark plug 32 interposed therebetween. Each injector 36 is connected to a fuel distribution pipe 38. The fuel distribution pipe 38 supplies high-pressure fuel supplied from the fuel supply system 40 to each injector 36.

  As shown in FIG. 1, an exhaust passage 42 that exhausts exhaust gas from the combustion chamber 10 is connected to the other side of the engine 1. The upstream end of the exhaust passage 42 is an exhaust manifold 44 that is branched and connected to the exhaust port 18 of each cylinder 2. A linear O2 sensor 46 for detecting the oxygen concentration in the exhaust gas is disposed at the collection portion of the exhaust manifold 44. The linear O2 sensor 46 detects the air-fuel ratio based on the oxygen concentration in the exhaust.

  Further, the upstream end of the exhaust pipe 48 is connected to the collecting portion of the exhaust manifold 44. A three-way catalyst 50 and a NOx absorption catalyst 52 are attached to the exhaust pipe 48 in order from the upstream side to the downstream side. The NOx absorption catalyst 52 adsorbs NOx when the oxygen concentration in the exhaust gas is high, releases NOx adsorbed as the oxygen concentration decreases, and reduces the released NOx by HC, CO, etc. in the exhaust gas. It is an adsorption reduction type catalyst.

  The exhaust pipe 48 is connected to an upstream end of an EGR passage 54 that recirculates a part of the exhaust gas to the intake system. The downstream end of the EGR passage 54 is connected to the intake passage 24 between the throttle valve 28 and the surge tank 30. The EGR passage 54 is provided with an EGR valve 56 whose opening degree can be adjusted electrically.

  As shown in FIG. 1, the engine 1 includes an ECU (engine control unit) 58. The ECU 58 receives output signals from various sensors such as a crank angle sensor 60 that detects the rotation angle (engine speed) of the crankshaft 12, the airflow sensor 26, the linear O2 sensor 46, and the accelerator opening sensor 62, Based on the input output signal, the operations of the ignition circuit 34, the injector 36, the electric throttle valve 28, the EGR valve 56, and the like are controlled.

Fig.5 (a) shows the control map used by the fuel-injection control performed in the engine 1 of this embodiment. As shown in FIG. 5 (a), in the engine of the present embodiment, split injection control in which fuel is injected separately into an intake stroke and a compression stroke, and fuel is injected once in an intake stroke, under the control of the ECU 58. The batch injection control to be performed is performed by switching.
That is, in the engine of the present embodiment, split injection is performed from a low load in the engine low rotation region, a high load in the middle rotation region, a medium load in the high rotation region, and a batch injection in the other regions. Yes. In general, in a direct-injection gasoline engine, the air-fuel mixture is easily homogenized in the middle rotation region. Therefore, in the present embodiment, the split injection is performed only in the high load region in the middle rotation region. In the middle rotation region, a configuration in which divided injection is not performed even in a high load region may be employed.

  Also, as shown in Fig. 5 (b), the control characteristics are set so that the load for starting batch injection or split injection becomes high in the high rotation range for an engine aimed at homogenization in the high rotation range. May be. In the case of such an engine, the homogeneity deteriorates in the collective injection as the rotational speed becomes lower. Therefore, the load for starting the divided injection is set lower as the rotational speed becomes lower.

  Further, in an engine aiming at homogenization in a low rotation range, as shown in FIG. 5C, control characteristics for performing split injection on the high load side in the entire rotation range may be set.

  In the divided injection of the present embodiment, as shown in the time chart of FIG. 6, fuel injection is performed three times in total, once in the intake stroke and twice in the compression stroke. The injection in the intake stroke is preferably performed in the middle of the intake stroke where the flow velocity of the intake flow is high. Specifically, the injection timing in the intake stroke is such that the injection starts at 0 ° to 100 ° after top dead center (ATDC) and completes at 100 ° to 200 ° after top dead center (ATDC). It is preferable to set the injection timing in the stroke, and it is more preferable to set so that the injection timing exists in the range of 60 ° to 120 ° after top dead center (ATDC).

  The first injection in the compression stroke is, for example, before the compression top dead center (BTDC) 30 ° to 140 after the middle of the compression stroke, which is the time when the cylinder pressure becomes high and the movement of the injected fuel is suppressed. It is preferably performed at the time of °.

  Further, the second injection in the compression stroke is, for example, before the compression top dead center (BTDC) 0 ° to 90 ° after the middle of the compression stroke, which is a time when the piston approaches the top dead center and the injected fuel is pushed up. It is preferred to be done at the time.

The injection amount Q1 of the fuel injection in the intake stroke, the injection amount Q2 of the first fuel injection in the compression stroke, and the injection amount Q3 of the second fuel injection in the compression stroke are: Q1> Q2 ≧ Q3 It is set to satisfy the relationship.
Further, the fuel injection amount is set so that the relationship of Q2> Q3 is satisfied in the high load region and the relationship of Q2 ≧ Q3 is satisfied in the other regions.

  Next, the arrangement of the plurality of nozzle holes 64 formed at the tip of the injector 36 will be described. FIG. 7 is a view showing the arrangement of a plurality of nozzle holes at the tip of the injector 36. As shown in FIG. 7, the injector 36 of the present embodiment has three nozzle holes (upper nozzles) 64 a, 64 b, 64 c arranged above, and three nozzle holes (lower nozzles) arranged below. ) 64d, 64e, 64f. In this embodiment, each nozzle hole has the same diameter (about 0.15 mm), and further, the spread (injection angle) of fuel injected from each nozzle hole is the same at about 20 degrees.

FIG. 8 schematically shows a three-dimensional inclination angle between the axis L of the injector 36 and the axes 66a, 66b, 66c, 66d, 66e, 66f of the nozzle holes 64a, 64b, 64c, 64d, 64e, 64f. It is a figure.
As shown in FIG. 8, the axial centers 66a and 66b of the upper injection holes 64a and 64b, that is, the fuel injection direction (center axis of the injected fuel) are respectively left and right of the electrode part 32a of the spark plug 32. It is arranged to be oriented to the area. Furthermore, the axis 66c of the other upper nozzle hole 64c is arranged so as to be directed to the lower region of the electrode portion 32a.

  The lower nozzle holes 64d, 64e, and 64f are arranged such that their axial centers 66d, 66e, and 66f are directed toward the crown surface of the piston 8. At the same time, the shaft centers 66d, 66e, 66f of the lower nozzle holes 64d, 64e, 64f are below the locus of maximum lift of the left and right intake valves shown by the one-dot chain line in FIG. It is directed upward from the end of the piston 8 located at the position. That is, the fuel injected from the lower injection holes 64d, 64e, and 64f passes under the intake valve that is lifted to the maximum, and even when the piston 8 is at the bottom dead center, Arranged to be oriented.

  Further, the lower nozzle holes 64d, 64e, and 64f are arranged so that their axial centers 66d, 66e, and 66f are respectively directed inside the opening edge 9a of the cavity 9 when the piston 8 is in the intermediate position. .

  FIG. 9 is a drawing showing the relationship between the angles between the axes of adjacent nozzle holes and the injection angles from these nozzle holes. As shown in FIG. 9, in the injector 36 of the present embodiment, the angle Θ formed by the axis 66c of the upper nozzle 64c and the axis 66f of the lower nozzle 64f adjacent to the upper nozzle 64c is the compression stroke. Is set to a larger angle than the sum of the angle 1/2 of the injection angle α of the fuel injection from the upper injection port 64c and the angle of one half of the injection angle β of the fuel injection from the lower injection port 64f in the compression stroke. ing.

Here, the definition of the injection angle α (β) described above will be described with reference to FIG. The injection angle α (β) refers to the opening angle of the geometric fuel injection area from the injector 36. The geometric fuel injection area is a droplet area of fuel spray when there is no intake flow in the combustion chamber 10.
Hereinafter, specific examples will be described. As shown in FIG. 10, at a position 20 mm downstream from the injection hole A point of the injector 36, two points B and C where the imaginary plane through which the spray center line passes and the contour of the fuel spray intersect are determined, and the injection angle is expressed by ∠BAC Let α (β) (α = ∠BAC).

As an actual measurement method of the injection angle α (β), for example, a laser sheet method is used. That is, first, a sample of a dry sol belt corresponding to the fuel property is used as the fluid ejected by the injector 36, and the pressure of this sample is a predetermined value (for example, 12 MPa) within the range of the fuel pressure actually used at room temperature. Set to. Moreover, as an atmospheric pressure, the pressure vessel provided with the laser passage window which can image | photograph spraying, and the window for a measurement is pressurized to 0.5 Mpa, for example. Then, a drive pulse signal having a predetermined pulse width is input to the injector 36 to inject fuel so that the fuel injection amount per pulse becomes 9 mm ³ / stroke at room temperature. At this time, a laser sheet light having a thickness of 5 mm is irradiated to the fuel spray so as to pass through the spray center line, and a spray image is taken with a high-speed camera from a direction orthogonal to the laser sheet light surface. Take a picture. Then, the injection angle α (β) is determined in accordance with the above definition based on the imaging screen 1.56 milliseconds after the input timing of the above drive pulse signal.
Note that the spray contour in the photographed image is the contour of the droplet-shaped sample particle area, and since the sample particle area is brightened by the laser sheet light, the spray is sprayed from the portion where the brightness changes in the photographed image. I try to figure out the outline.

  In the present embodiment, the injection angle of each of the nozzle holes 64a, 64b, 64c, 64d, 64e, and 64f is 20 °, and the angle Θ formed by the axis 66c of the upper nozzle 64c and the axis 66f of the lower nozzle 64f is 30. Set to °. In other words, in the present embodiment, the axis of the closest upper nozzle hole and the axis of the lower nozzle hole are separated by 20 degrees or more.

  With such an arrangement, the conical path of the fuel injected from the upper nozzle 64c and the lower nozzle 64f adjacent to the upper nozzle 64c does not overlap. Therefore, the fuel injected from the upper nozzle and the fuel injected from the lower nozzle ( There is no mutual interference between the sprays, and the contact between the sprays is prevented.

  FIG. 11 is a drawing showing the relationship between the angles between the axes of adjacent lower nozzle holes and the injection angles from these nozzle holes. As shown in FIG. 11, the opening angle Φ of the axial centers 66d and 66f of the adjacent lower injection holes 64d and 64f is an angle that is half the injection angle γ of the fuel injection from the lower injection hole 64d in the compression stroke. And an angle equal to or less than the sum of the angle ½ of the injection angle δ of the fuel injection from the lower injection port 64f in the compression stroke. Similarly, the opening angle of the axial centers 66e and 66f of the adjacent lower nozzle holes 64e and 64f is also half of the injection angle of fuel injection from the lower nozzle hole 64e in the compression stroke and from the lower nozzle hole 64f in the compression stroke. The angle is set to be equal to or smaller than the sum of the angle of the fuel injection and one-half of the injection angle.

  As described above, the opening angles of the axis lines 66d, 66e, 66f of the lower nozzle holes 64d, 64e, 64f are set to be smaller than 20 degrees, so that the fuel injection from the lower nozzle holes 64d, 64e, 64f of the lower nozzle holes is performed. The conical paths will overlap and the injected fuel will attract and interfere with each other.

  The fuel injected from the adjacent lower injection holes 64d and 64f (and 64e and 64f) will fly toward the cavity of the piston 8 while attracting each other while interfering with each other. Adhering to is suppressed.

The present invention is not limited to the above-described embodiments, and various changes or modifications can be made within the scope of the technical matters described in the claims.
In the above embodiment, the fuel is divided and injected in the high load or high rotation region. However, the fuel may be injected into the high load or high rotation region from the beginning or the middle of the intake stroke. According to such a configuration, the homogeneity of the air-fuel mixture is improved.
Furthermore, the number and arrangement of the upper nozzle holes and the lower nozzle holes are not limited to the above-described embodiment, and can be changed as appropriate according to engine conditions and the like.

It is drawing which shows schematic structure of the spark ignition direct injection engine of preferable embodiment of this invention. It is sectional drawing to which the combustion chamber vicinity of the engine of FIG. 1 was expanded. It is a top view which shows the piston crown surface of the engine of FIG. FIG. 4 is a sectional view taken along line IV-IV in FIG. 3. 2 is a control map of fuel injection control performed in the engine of FIG. 1. It is a time chart of the fuel injection at the time of the division | segmentation injection in the engine of FIG. It is drawing which shows arrangement | positioning of the nozzle hole in the engine of FIG. It is the figure which showed typically the three-dimensional inclination | tilt angle of the axial center of an injector, and the axial center of each nozzle hole. It is typical drawing which shows the relationship between the angle between the axial center of an adjacent upper nozzle hole and a lower nozzle hole, and the injection angle from each nozzle hole. It is explanatory drawing explaining the definition of the injection angle which concerns on embodiment of this invention. It is a typical drawing which shows the relationship between the angle between the axial centers of an adjacent lower nozzle hole, and the injection angle from each nozzle hole.

Explanation of symbols

1: Engine 2: Cylinder 10: Combustion chamber 20: Intake valve 22: Exhaust valve 32: Spark plug 36: Injector 64: Injection holes 64a, 64b, 64c: Upper injection holes 64d, 64e, 64f: Lower injection holes 66a, 66b, 66c, 66d, 66e, 66f: axial center of the nozzle

Claims (7)

A combustion chamber constituted by a cylinder, a cylinder head, and a piston; an ignition plug having an electrode portion disposed at an upper center of the combustion chamber; an intake valve disposed at a ceiling portion of the combustion chamber; and the ignition plug An exhaust valve disposed at a position opposed to the intake valve across the fuel cell, an injector disposed adjacent to the intake valve and injecting fuel into the combustion chamber, and fuel injection control for controlling fuel injection from the injector A spark ignition type direct injection engine comprising: an injector having an upper injection hole directed to the electrode portion; and a plurality of lower injection holes directed to the piston;
The angle formed by the axis of the upper nozzle and the axis of the lower nozzle adjacent to the upper nozzle is a half of the injection angle of fuel injection from the upper nozzle in the compression stroke, and the angle in the compression stroke. Is set to an angle greater than the sum of the angle of the fuel injection from the lower nozzle adjacent to the upper nozzle
The angle between the axial centers of two lower nozzle holes adjacent to each other among the plurality of lower nozzle holes is a half of the injection angle of fuel injection from one of the two lower nozzle holes in the compression stroke, and the compression stroke. Is set to an angle that is equal to or less than the sum of the angle of the fuel injection from the other of the two lower injection nozzles at one half .
The upper nozzle hole is composed of three nozzle holes whose axial centers are directed to the left and right and lower regions of the spark plug,
The lower nozzle hole is composed of three nozzle holes whose axis is directed to the piston through the lowermost position of the intake valve.
This is a spark ignition direct injection engine. The piston has a cavity formed on the crown surface and opening upward;
The axis of the lower nozzle hole is arranged so as to be directed into the opening edge of the cavity of the piston located at an intermediate height position of the cylinder,
The spark ignition direct injection engine according to claim 1 . The opening of the cavity has an oval shape whose long axis extends from the end on the exhaust valve side of the crown surface toward the end on the intake valve side,
The spark ignition direct injection engine according to claim 1 or 2 . The cavity gradually becomes deeper from the intake valve side toward the exhaust valve side,
The spark ignition direct injection engine according to any one of claims 1 to 3 . The fuel injection control means is configured to execute fuel injection from the initial stage of the intake stroke in a high load or high rotation range;
The spark ignition direct injection engine according to any one of claims 1 to 4 . The fuel injection control means causes the fuel injection to be executed in the middle of the intake stroke in a high load or high rotation range;
The spark ignition direct injection engine according to any one of claims 1 to 5 . The angle formed by the axis of the upper nozzle and the axis of the lower nozzle adjacent to the upper nozzle is set to 20 ° or more.
The spark ignition direct injection engine according to any one of claims 1 to 6 .

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